Selective wave-transmissioit system



J. H. HAMMOND, JR;

SELECTIVE WAVE TRANSMISSION SYSTEM. APPLICATION FILED APR. 30, 1912. RENEWED 1AN.B. I919.

' 1,326,727. Patented Dec. 30,1919.

2 SHEETSSHEETI WITNESSES v ioinfik ymm d, l/WENTOR y M JMA TTORNEYS 1. H.'HAMMO-ND, JR;

SELECTIVE WAVE TRANSMISSION SYSTEM. APPLICATION FILED APR. 30,1912. RENEWED JAN. 8| 1919.

' Patented Dec. 30, 1919.

2 SHEETS-SHEET 2.

WITNESSES Arl v l; l llg 'lll N I j I JAnE fiQm S I i S 87 I 9M ATTORIIEYS x0411. INVENTOR JOHN HAYS HAMMOND, JR, Oi GLOUCESTER, MASSACHUSETTS.

SELECTIVE WAVE-TRANSMISSION SYSTEM.

Specification of Letters Patent.

Patented Dec. 30, 1919.

Application filed April 30, 1912, Serial No. 69 1;185. Renewed January 8, 1919. Serial No. 270,246.

To all whom it may concern:

Be it known that I, JOHN HAYS HAM- noxo, J12, a citizen of the United States, residing at Gloucester, in the State of Massachusetts, have invented certain new anduseful Improvements in Selective Wave-Transmission Systems, of which the following is a specification.

My invention relates to systems of selective wireless transmission of energy, in which electric waves of definite frequencies are transmitted in groups also having definite group frequencies, and relates more particularly to systems in which electric waves oftwo or more wave lengths and in grou iis of two or more frequencies are transmitted simultaneously.

My invention consists broadly in the transmission of radiant energy from one point in groups of waves having two or more group frequencies, the waves comprismg each group having one definite wave length. but havmg'diiferent wave lengths 1n the different groups, and the receiving ofv this energy at another place so as to effect the selective control of suitable mechanisms.

The apparatus I have employed to illustrate this invention relates to the operation of a typewriter keyboard by means of cornbinations of two or more groups of electric waves, both the wave groups and the individual waves being tuned to definite frequencies, as will hereafter be set forth more fully, but my invention is not confined to this particular embodiment, but may be applied in many other ways.

In order to effect the operation of 45 keys on a typewriter keyboard by means of radiant energy, it is usually necessary to have to separate circuit-closing relays, or other suitable controlling mechanisms, each operated by waves of a certain frequency, or group frequency, set out from a transmitting station by suitable apparatus for the production of these 4,5 varieties of waves or wave groups. But with my system it is possible to operate the 45 keys with only 10 relays, or other suitable apparatus, acting in comliilmtions of two, connected in such a Way that both must be energized simultaneously to operate the key which they control.

In order that these 10 relays may be selectively operated by means of radiant en er it is necessary to have. at the transmitting station. 10 transmitting units, and at the receiving station, 10 corresponding receiving units, one for the control of each relay. In my system each of these units is tuned to a definite wave length and a defimte spark, or group frequency, and istherefore doubly selective. Moreover, since each key can only be operated by two relays acting simultaneously, each key has a quad.

ruple selectivity, and the-chances of any outslde interference with the operation of these keys are practically negligible.

In the accompanying drawings;- -Flgure 1 represents, in diagrammatic form, a transmitting station on my system,

and

2 shows, also diagrammatically, a receiving station.

In Fig. 1 are shown 10 transmitter units, numbered from I to X, inclusive, which in combinations of two, are controlled by 45 keys, numbered from 1 to 45, inclusive. Each unit emits groups of waves having a distinct group frequency and a distinct ,wave length, and it is composed of an alternating-current generator G, a step-up transformer, T, and a closed oscillatory circuit comprising a spark gap S, a variable condenser C, and an inductance coil L. B and D are shortcircuiting strips which close the circuits through generator and transformer of transmitter units I and II when key 1 is operated. A is an untuned antenna in inductive relation to all 10' oscillatory circuits.

In the operation of the transmitting apparatus, when key 1 is closed, transmitter units I and II, each with its distinctive wave length and group frequency, impress their oscillations uponthe antenna A and cause the latter to radiate energy of two wave lengths and at two group frequencies. When key 28 is closed, transmitter units IV and VIII impress upon the antenna oscillations of their respective wave lengths and group frequencies, which are then radiated out ward. In a similar way, each key controls two of the transmitter units, each of which emits waves of distinct wave length and group frequency.

In Fig. 2, there are 10 receiver units, 1 to X inclusive, tuned, respectively, to the 10 transmitter units. A is an untuned antenna. I is a receiver unit, comprising a closed oscillatory circuit consisting of the inductance coil l1 and the variable condensers this circuit being tuned to the wave length of the correspoinling oscillatory circuit of the transmitter unit I. The rectifier R allows unidirectional currents to pass through the coupling coil L, which is in inductive relation to coupling coil L the latter and the varable condenser C being in a comparatively vlow frequency circuit which is tuned to the group, or spark frequency of transmitter unit I. Rectifier R allows unidirectional currents to pass through the relay F which short circuits the bus-bars M and N. The other receiver units function in an exactly similar manner.

There are 45 printing elements numbered from 1 to 45 inclusive, and in the operation of the receiving apparatus, w'hen printer 1 is to work, relays F and F must be closed, which causes the closure of a cir cuit through a source of current and an electromagnet, which causes printer 1 to operate. This requires the simultaneous operation of receiver units I and II which can only be efiected when transmitter units I and II are emitting their characteristic waves, upon having been started by the closing of key 1. In a similar manner, any one of the 45 printers can be operated by clos ing the corresponding key of the transmitting apparatus.

The particular apparatus here described is suitable for the transmission and receiving and recording of telegraphic signals and messages, but it is obvious that my invention has a far wider scope. A great variety of wave lengths and of forms of radiant energy can be utilized, and a large number of mechanisms can be actuated thereby. A tuned relay or any other device which responds to a specific frequency of impulses received may be used at the receiving station.

I do not confine myself to the particular means here shown for carrying out my invention, but what I claim is:

1. In a selective wave transmission system, a receiver comprising a plurality of sets, each of said sets comprising a plurality of tuned circuits and being responsive to a predetermined combination of wave lengths and group frequencies, said sets operating in predetermined combinations, two or more, to actuate local mechanisms.

2. In a selective wave transmission system, a transmitting apparatus comprising a' 4. In a radio typewriter system, a receiving station comprising receiving circuitstuned to wave length and group frequency, and typewriter keys each operated directly by combinations of'two or more of saidreceiving circuits.

5. A selective receiving system for waves comprising a plurality of elements selectively responsive respectively to a plurality of differentiated series of'wa'ves, each series having a wave frequency and a wave group frequency different from the wave frequency and wave group frequency of every other series, and a plurality -bf devices each of which is. independently controlled as a result of the combined action of a plurality of said elements, the number of said devices. being greater than the number at said eleinents.

6. A selective receiving system for waves comprising a plurality of elements selectively responsive respectively to a plurality of differentiated series of waves, each series having a wave frequency and, a wave group frequency different from the wave frequency and wave group frequency of every other series, and a plurality of devices each of which is independently controlled as a result of the combined action of a plurality ofsaid elements the number of said devices being greater than twice the number of said elements.

7. A selective receiving system for waves comprising a plurality of elements selectively responsive respectively to a plurality of differentiated series. of waves, each series having a wave frequency and a wave group frequency different from the wave frequency and wave grou frequency of every other series, and a p urality of devices each of which is independently controlled as a result of the combined action of a plurality of said elements, each of said elements being arranged to cooperate selectively with any one o a plurality of the remaining elements to actuate a corresponding device.

'8. A selective receiving system for waves comprising a plurality of electromagnetic elements, means for selectively energizing ,any one of said elements independently of to a'plurality of the remaining elements and I forming therewith a plurality of said groups.

10. In a radio typewriter system, a receiving station comprising a plurality of sets each .comprising circuits tuned to wave frequency and group frequency respectively, and typewriter keys each operated directly by a combination of a plurality of said sets.

11. In a radio system, a receiving station comprising a pluralitv of sets each comprising circuits tuned to wave frequency and group frequency respectively, and typewriter keys each independentl operated b a, combination of a plurality of said sets, thenumber of said keys-being greater than the number of said sets,

12. In a radio system, a receiving station comprising a plurality" of sets each comprising receiving circuits tuned to wave frequency and group frequency respectively, and operative elements each independently operated by a combination of a plurality of said receiving circuits.

13. In a selective, wave receiving system,

' a receiver comprising a plurality of sets, each --:0f said sets comprising a plurality of cirruits tuned to different frequencies respectively, and a plurality of ope'ratlve elements each independently operated as a result of the action of a predetermined combmation of a plurality of said sets. V

14. In a selective wave receiving system, a receivercomprising a plurality of sets, each of said sets comprising a plurality of sue cessively acting circuits tuned to different frequencies respectively, and a plurality of operative elements each independentlv operated as a result of the action of a predetermined combination of a pluralityof said sets.

15. In a selective wave receiving system,

a receiver comprising a plurality ofv sets,

each of said sets comprising a plurality of circuits tuned to different frequencies respectively, and a plurality of operative elements each indepemlentlv operated as a re sult of the action of a predetern'iined combination of a pluralit of said sets, the number of said elements being, greater than the number of said sets.

16. Ina selective wave receiving system, a receiver comprising a plurality of sets, each comprising a plurality of circuits tuned to different frequencies respectively. and a plurality of operative elements, each inde pendently operated as a result of the simultaneous action of a predetermined combination of a plurality of said sets. 17. In a selective wave receiving system,

a receiver comprising a plurality of sets, each comprising a plurallty of clrcults tuned to difi'erent frequencies respectively, and a pluality of ope 'ative elements, each independently operated as a result of the simultaneous action of a predetermined combination of a plurality of said sets. the number of said elements being greater than the number of said sets. a

18. In a radio typewriter system, a reeeiving station comprising receiving circuits tuned to wave length and group frequency, and typewriter keys each operated directly by a plurality of said receiving circuits.

19. A selective receiving system for waves comprising a plurality of elements selectively responslve respectively to a plurality of differentiated series of waves, and a plurality of devices each of which is independently controlled as a result of the combined action of a plurality of said elements, the number of said devices being greater than the number ofsaid elements.

20. A selective receiving system for waves comprising a plurality of elements selectively responsive to a plurality of differentiated series'of waves, anda plurality of devices each of which is independently controlled a a result of the combined action of a plurality of said elements, the number of said devices being greater than twice the number of said elements.

21. A selective receiving system for waves comprising a plurality of elements selecrality of devices each of which is independently controlled as a result of the combined action of a plurality of said elements, each of said elements being ar 'anged to coopeu ate selectivelywith any one of a plurality of the remaining elements to actuate a corresponding device.

22. A selective receiving system. for Waves, comprising a plurality of electromagnetic elements, mean responsive to radiant energy for selectively energizing any one of said elements independently of the remaining elements, and a plurality of devices electrically connected to different groups of said elements respectively whereby when the elements of any one of said groups are simultaneously operated the corresponding one of said devices will be operated, the number of said device being greater than the number of said elements.

23. A selective receiving system for waves comprising a plurality of electromagnetic elements, means responsive to radiant energy for selectively energizing any one of said elements independently of the remaining elements, and a plurality of devices electrically connected to different groups of said elements respectively whereby"wl1en the elements of any one of said groups are simultaneously operated the corresponding oneof said devices will be operated, the number of said devices being greater than the number of said elements, each of said elements being electrically connected to a plurality of the remaining elements and forming therewith a plurality of said groups. y

24. In a selective Wave receiving system, a receiver comprising a plurality of sets,

, each of said sets comprising a plurality of elements tuned to different frequencies're 26. In a selective wave receiving system,

a receiver comprising a plurality of sets, each ofsaid sets com rising a plurality of elements tuned to diii erent frequencies respectively, and a plurality of operative element each independently controlled as a result of the action of a predetermined combination of a plurality of said sets, the number of said operative elements being greater than the number of said sets.

27. In a selective Wave receiving system,

different Wave frequencies respectively, and

said plurality of series of Waves being pe-- riodically modified respectively at different frequencies respectively, and means including a plurality of keys arranged to connect one of said units operatively to any one of the remaining units.-

29. A wave transmission ystem comprising a plurality of transmitting units for transmitting a plurality of series of groups of Waves respectively having 'difierent Wave frequencies and different group frequencies respectively, of mean for selectively connecting any one of said units operatively' with any one of the remaining units so as to cause the units thus connected to transmit simultaneously two corresponding series of W. ves.

This specification signed and witnessed this 23rd day of April, A. 1)., 1912.

JOHN HAYS HAMMOND, JR.

Signed in the presence of- BENJ. F. Mrnssrznn, M. P. WINXE. 

